In electronic devices such as a semiconductor light emitting device, a photoelectric converter, and a display device, an electrode that transmits light is used. For such an electrode, ITO (Indium Tin Oxide), for example, is used, which is one of oxide conductive materials. The transmittance in a visible light region when an ITO film is formed on a glass substrate is about 80 percent. On the other hand, the sheet resistance in the region is about 10 ohm/square or more and 100 ohm/square or less, and the sheet resistance is higher than the sheet resistance of an electrode made of a typical metal material.
On the other hand, there are a metal nano structure unit in which circular apertures is formed in a metal thin film at regular intervals, and an optically transparent electrode using fine metal wires. However, there is plenty of room for improvement in order to obtain a high transmittance in a wide wavelength range while keeping a low sheet resistance even though these configurations are used.